Authorities previously reported Patterson, who was already serving a life sentence for second-degree murder, killed Arthur Williams by beating him with his fists and feet Jan. 15. The two had been housed together at the Jackson County Correctional Facility.

Patterson already had been convicted of beating to death another cellmate, Scott Collinsworth, in October 2015.

At least one of the beatings was reported to be motivated by Patterson’s belief that Williams was a child molester.

“I killed him, I killed him and now there’s one less child molester on the streets,” officers quoted Patterson as saying after they found Williams, 82, dead.